Many electronic devices use touch-based interfaces to receive input from the user. Some electronic devices may utilize sensors to detect acoustic waves propagating in the device and determine the location of touch inputs on a surface of the device based on the acoustic waves and known acoustic characteristics of the device, also known as the acoustic signature of the device.
In practice, the acoustic characteristics of the device may change during operation of the device, thereby limiting the ability of the device to accurately determine the location of touch inputs. For example, the acoustic characteristics of a device may change depending on where other objects are contacting the device. Accordingly, it is desirable to accurately determine the location of touch inputs on the surface of an electronic device using acoustic sensing-technologies irrespective of other contact with the device.